This invention relates to a method for replacing a worn excavating tooth point and, more particularly, to the use during installation of a novel locking pin means.
Since before the turn of the century, excavating teeth have included replaceable points mounted on adapters which, in turn were secured to the digging edge of an excavator. Depending upon the type of excavation, a given adapter can be successively equipped from anywhere from 5 to 30 points to maintain sharp penetrating edges. Historically, the point and nose of the adapter were equipped with vertically aligned openings in which a locking pin was received. An early version is seen in U.S. Pat. No. 564,664. In the early 1980's a new form for securing the point to the adapter was developed as shown in co-owned U.S. Pat. No. 4,335,532. This made use of helical thread means on the point nose and adapter socket with a side-mounted pin means. Subsequently, for smaller sizes of teeth, the pin means was dispensed with and detent means were provided on rearwardly extending tongues as seen in co-owned U.S. Pat. No. 4,557,423. For the larger sizes, an improved side lock was provided as seen in co-owned U.S. Pat. No. 4,761,900. We have now found that certain of the smaller sizes function better with modified side pin lock means as described hereinafter.
It will be appreciated that the securement of the point on the adapter is a compromise between two opposing demands. The way of securing must be strong enough during the excavating operation so as to maintain the point on the adapter against the tremendous shock loads encountered. Yet, when replacement is necessary, the means for securement must be readily removed. It will be further appreciated that often the replacement is performed under rather primitive conditions in the field where no assistance equipment is available. Typically, the locking pin has to be removed with only a hammer and drift pin which makes it difficult to overcome a tightly held securement.
According to the invention, the balance of opposing requirements is achieved through the provision of a novel locking pin for side mounting where the pin is readily removed by shearing a sidewardly extending upper flange. However, during operation, the pin provides means in the form of a forwardly extending rib which counteracts any twisting tendency in its assembly in the point and the adapter which would tend to bring about undesirable removal, and means in the form of a resilient hook which counteracts any dislodgement tendency.
Other advantages and details of operation can be seen in the ensuing specification.
The invention is described in conjunction with the accompanying drawing, in which
FIG. 1 is a fragmentary exploded view of one embodiment of the invention;
FIG. 2 is a fragmentary side elevational view of the elements of FIG. 1 in assembled condition;
FIG. 3 is a fragmentary sectional view such as would be seen along the sight line 3--3 of FIG. 2;
FIG. 4 is a view similar to FIG. 3 but with the parts thereof during disassembly;
FIG. 5 is a fragmentary top plan view such as would be seen along the sight line 5--5 applied to FIG. 2;
FIG. 6 is a view similar to FIG. 5 but of a modified form of pin lock;
FIG. 7 is a front elevational view of the pin means seen in perspective in FIG. 1;
FIG. 8 is an enlarged sectional view taken along the sight line 8--8 applied to FIG. 7;
FIG. 9 is a view similar to FIG. 8 but showing flexing of a lower web incident to installation;
FIG. 10 is a top plan view of an assembled tooth featuring a further modified form of pin means;
FIG. 11 is an exploded side elevational view of the assembly of FIG. 10;
FIG. 12 is an enlarged top plan view of the portion encircled in FIG. 10;
FIG. 13 is a sectional view such as would be seen along the sight line 13--13 applied to FIG. 11 and wherein the locking pin is also shown in spaced or exploded position;
FIG. 14 is a top plan view of a tooth assembly featuring yet another pin lock of the invention;
FIG. 15 is an exploded side elevational view of the assembly of FIG. 14;
FIG. 16 is an enlarged top plan view of the encircled portion of FIG. 14; and
FIG. 17 is a sectional view seen along the sight line 17--17 applied to FIG. 15.